CARTRIDGE HEATERS SPECIAL FEATURES

Electric Heater Special Features and Modifications

The following is an outline of Special Features and Modifications available with Backer Hotwatt Electric Heating Elements.It applies to all Standard, Superwatt, Square and Rectangular Cartridge Heaters and Immersion Heaters. Catalog Numbers have been assigned to all special features and modifications. Please provide an adequate description to avoid confusion when a special feature applies to more than one size or item. Special features for other heaters are covered in each specific section.

Lead Configurations

SF1: Flexible Leads for applications where leads can be bent close to end of unit.See specific unit size for maximum allowable amperage

Standard on:

In-Stock Standard and Superwatt Cartridge

Standard Cartridge: 1/8″ to 3/4″ and 1.9″ and 2 3/8″ diameter

Superwatt Cartridge: 1/4″ to 3/4″ diameter

Square and Rectangular: all sizes

Immersion: 1/4″ to 3/4″ and 1.9″ and 2 3/8″ diameter

Available on:

Standard Cartridge: 15/16″ to 1 1/4″ diameter

Immersion: 1″ and 1 1/4″ diameter

SF2: Leads for application where repairable leads are desired or when unit amperage will not allow the use of Type SF-1 leads.

Standard on:

Superwatt Cartridge: 1″ diameter

Available on:

Standard Cartridge: 3/16″ to 3/4″ diameter

Immersion: 1/4″ to 3/4″ diameter

SF3: Post terminals.

Standard on:

Standard Cartridge: 15/16″ to 1 1/4″ diameter

Immersion: 1″ to 1 1/4″ diameter

Available on:

Standard Cartridge: 3/4″ diameter

Immersion: 3/4″ diameter

SF4: Leads for application where lead space is minimum and it is desirable to bringleads out at right angles to sheath. Specify overall length of heater when ordering

SF7: Fiberglass sleeving. Additional sleeving over leads for protection.Leads are normally 2″ longer than sleeve.SF7A: Common sleeve. Single sleeve over both leads.SF7B: Individual sleeve. Single sleeve over each lead. Specify length of sleeve.Available on:

All products with leads

SF8: Silicone rubber sleeving. Additional sleeving over leads for protection and moisture resistance.SF8A: Common sleeve. Single sleeve over both leads.SF8B: Individual sleeve. Single sleeve over each lead. Specify length of sleeve. Leads are normally 2″ longer than sleeve.Available on:

All products with leads

SF9: Strain relief clip for leads subject to strain and pull.

Available on:

Standard Cartridge: 1/4″ to 3/4″ diameter with Type SF1 leads only

Superwatt Cartridge: 1/4″ to 3/4″ diameter with Type SF1 leads only

SF10: Ceramic bead insulation for leads subject to high temperatures up to 1000°F. Specify lengths of beads required when ordering.Available on:

All products with leads

Lead End Termination

SF11: Lugs, rings, quick connect terminals attached to the end of lead wires. Specify terminal type and size when ordering. Special terminals are available.Available on:

Stainless Steel Bushings

SF26: Units with flanges. Mounting hole centers for 1/4″ to 5/8″ diameter is 1 1/8″ and for 3/4″ diameter is 1 5/32″. Special flange sizes available upon request.

Available on:

Standard Cartridge: 1/4″ to 3/4″ diameter.

Superwatt Cartridge: 1/4″ to 3/4″ diameter.

SF27: Stainless steel riser and support feet for over the side immersion heaters.

Special Electrical Features

SF28: Three phase heaters.

Available on:

Standard Cartridge: 3/8″ to 2 3/8″ diameter.

Superwatt Cartridge: 3/8″ to 1″ diameter.

Immersion Heater: 3/8″ to 2 3/8″ diameter.

Square Cartridge: 3/8″ to 1/2″ square.

SF29: Multiple heat; when a single unit with multiple wattages is necessary.Some uses of these units include: quick heat-up with a standby circuit for maintenance of low temperature; providing different wattages when there is a wide variation in thermal loads; and replacing more expensive rheostats or powerstats for wattage control.

Available on:

Standard Cartridge: 3/8″ to 2 3/8″ diameter.

Superwatt Cartridge: 3/8″ to 1″ diameter.

Immersion Heater: 3/8″ to 2 3/8″ diameter.

Square Cartridge: 3/8″ to 1/2″ square.

SF30: Special wattage distribution for units requiring different concentrations of wattage over their heated length. Distribution should be specified as a percentage of wattage over a percentage of length, i.e. 36/25.

Available on:

All units over 3″ long.

SF31: Built in thermocouple. Junction at bottom of heater.Ungrounded thermocouple:

SF31-JU – Iron/Constantan – Type J

SF31-KU – Chromel/Alumel – Type K

Grounded thermocouple:

SF31-JG – Iron/Constantan – Type J

SF31-KG – Chromel/Alumel – Type K

Available on:

Standard Cartridge: 3/8″ to 2 3/8″ diameter.

Superwatt Cartridge: 1/4″ to 1″ diameter.

Square Cartridge: 3/8″ to 1/2″ square.

Rectangular Cartridge: 1/4″ by 1″ rectangular.

Immersion Heater: 3/8″ to 2 3/8″ diameter.

SF32: High voltage heaters from 300V to 600V. Consult factory for availability on items.

Maximum Voltage/Unit Size

Diameter

5/8″

3/4″

1″

1 1/4″

1.90″

2 3/8″

Std.Cart.

480V

480V

480V

600V

600V

600V

Superwatt

480V

480V

480V

NA

NA

NA

Immersion

480V

480V

480V

600V

600V

600V

Features Ohter Physical Features

SF33: Double end units. One terminal at end. Especially suitable for heating: warming closets, ovens, press heads, drying cabinets, platens and plates. Double end units (post type terminals at each end) can be installed in reamed holes or in machined grooves. The standard sheath material is stainless steel and cannot be bent or formed. Available with SF1 or SF3 terminations.